Ultraviolet stabilizers (also known as inhibitors or absorbers) are well-known. In the past, these ultraviolet stabilizers have been incorporated into polymeric materials in small amounts, usually less than 5% by weight to inhibit the degradation of the polymeric material when exposed to ultraviolet radiation. It has been recognized in the art that these ultraviolet stabilizers are difficult to handle in plastics compounding and plastics manufacturing processes. Many of these stabilizers were previously known to be solids at room temperature or above. Thus, in order to disperse the stabilizers uniformly throughout a product, they were many times applied as a powder or granules. Some stabilizers became tacky as the temperature increased. As a result in some manufacturing processes, the UV stabilizers which were solid at room temperature become tacky at the higher processing temperatures of some procedures. This tackiness made the UV stabilizer hard to disperse. As the temperature increased and the stabilizer became tacky, the stabilizer particles could ball together. Thus, many UV stabilizers have characteristics which rendered them difficult to utilize in the compounding of plastics.
In one aspect the present invention relates to the discovery that UV stabilizers can be rendered liquid at room temperature, and that the liquid can be rendered stable at room temperature (21.degree.-23.degree. C.). Further, it has been found that certain stabilizers or mixtures of stabilizers can be formed as a stable liquid down to 0.degree. C. These liquid stabilizers have the advantages that the stabilizer is easier to use in the manufacturing of plastics or coatings because the stabilizers are in a liquid form which is easily mixed and more uniformly dispersed within the other components of the polymeric material.
Thus, the invention offers the advantages of easier manufacture, and greatly increased ease in handling.